ITMI20071458A1 - WAFER PILOT VALVE - Google Patents

Description

DESCRIPTION OF THE INVENTION

by title

WAFER SHAPED PILOT VALVE

The present invention relates to a wafer-shaped pilot valve. The valve is a valve used as a pilot valve to control the opening and closing of a main valve, such as a pressure regulating valve, a pressure reducing valve, an electromagnetic valve, and a level regulating valve. water. A main valve housing or housing is sandwiched between pipe flanges, and is secured in this position by bolts traversing the flanges.

THE TECHNIQUE NOTE.

Traditional valves include single plate check valves and flangeless, wafer-shaped butterfly valves. In these wafer-shaped valves, a thin disc-shaped valve body swings or rotates within a thin cylindrical valve housing, through which the fluid flow is linearly regulated, thereby opening and closing the flow path. . These valves are relatively simple in structure and function (see for example the document “Valve Terms JIS B 0100-1984”, of the Japanese Industriai Standards Committee, Japanese Standards Association, first edition of 28 February 1985, p. 37, No.

10307, p. 38, No. 10705).

There are also pilot valves which are divided into internal pilot valves and external pilot valves.

An internal pilot valve comprises a main valve and a pilot valve integrated into one unit.

An external pilot valve comprises a pilot valve and a main valve that are separated from each other and connected by piping.

In both types of valves, the valve housing enclosing the main valve results in an S-shaped flow path extended from its inlet to its outlet and designed so that the valve can be closed completely and speed regulated. of flow.

There are also widespread and generalized use of so-called flanged pilot valves, in which the terminal sections of connection with the pipes are flanged (see for example the Japanese patent with publication number 3-156617, Fig. 1).

However, a wafer-shaped pilot valve has not been developed so far. The possible reason for this is that the structure of a wafer-shaped pilot valve may not be as simple as that of a single plate check valve, such as the wafer-shaped one described above. A pilot valve requires a somewhat high force for the direct actuation of the main valve with a spring or similar. In many cases, a pilot valve includes a large diaphragm and a large piston or the like, since the elements that make up the actuation section of the main valve, the flow rate and the piping are also large.

If the valve housing enclosing the main valve has flanges as in the case described above, it turns out that the valve itself is not only heavy, but its manufacturing costs also increase at least by the value of the material required for the flanges.

In view of the circumstances described above, it is an object of the present invention to provide a wafer-shaped pilot valve in which the housing enclosing the main valve has no flanges, and the valve housing is sandwiched between the piping flanges. and fixed in this position by tightening the flanges of the pipes together with nuts and bolts, so as to install the pipes themselves.

SUMMARY OF THE INVENTION

To achieve the above-described object, a wafer-shaped pilot valve according to the present invention, adapted to control the motive force necessary to operate a main valve and open and close the main valve itself comprises:

- a casing or casing of the main valve, where said casing is sandwiched between the flanges of pipes tightened together with nuts and bolts and said casing has no flanges in its terminal sections for connection to said flanges and is equipped with a inlet and outlet for a pressurized fluid; And

- a cover flange neck extending from said valve housing upwards, said cover flange neck comprising a space to allow passage of a fluid under pressure, and being capable of accommodating only a valve stem passing through the same, said valve stem coupling said main valve to a control section to control the opening of said main valve according to a pressure variation provided by said pilot valve, where said cover flange neck is restricted only at the sides in the areas of its side walls corresponding to said bolts adjacent to each other, according to a width less than the interval between said bolts which may be different according to the type of said pipe flanges suitable for the size of said valve, so that said neck of the cover flange can be introduced through the space between said through bolts in det the flanges and adjacent to each other along the perimeter of said flanges.

A coupling surface of each of said connection terminal sections to be coupled to said flanges can also be hollowed to form an annular groove, and a sealing element can be inserted in said annular groove.

In conclusion, in the pilot valve of the present invention, the housing of the main valve is sandwiched between the flanges of the pipes tightened together with nuts and bolts. The terminal connection sections of the valve housing to be connected to the flanges, which are equipped with inlet and outlet for the fluid under pressure, are also respectively without flanges. Compared to the flanged valve, the overall weight of the valve can be significantly reduced, the interfacial dimension (i.e. the dimension between the connecting end sections) can be shortened, and the number of bolts required for piping installation can be reduced to half. In addition, the space to install the enclosure between the piping elements can be reduced, and the work required for piping installation can be done efficiently. The load applied to the elements of the piping assembly once completed can also be reduced, and the material costs required for the flanges can be eliminated, thus helping to significantly reduce manufacturing costs.

The neck of the cover flange is also extended from the main valve housing upwards, and includes a space inside to allow the passage of a fluid under pressure. The valve stem that connects the main valve to the control section to control the opening of the main valve according to the variation in pressure provided by the pilot valve is therefore the only one to pass through the space in the neck of the cover flange. To allow this cover flange neck to pass through the space between the bolts inserted into the piping flanges and adjacent to each other along the perimeter of the flanges, the cover flange neck is narrowed to form a section of width less than that of the space between the bolts, which will vary according to the types of flanges chosen according to the size of the valve itself. Specifically, the neck of the cover flange is restricted only in the areas of the side walls which correspond to the adjacent bolts. When the valve is sandwiched between the elements of the pipes equipped with flanges in their end sections, the narrow section of the neck of the opening flange avoids the adjacent bolts present along said flanges. In this way the neck of the cover flange can pass through the space between the adjacent bolts, without obstructing the bolts themselves. The bolts can then be screwed through all the flange holes without presenting any problems. Consequently, thanks to a simple tightening of the bolts with the nuts, the valve can be interposed between the elements of the pipes without any difficulty.

According to the present invention, even if the space between the bolts varies according to the type of the flanges of the pipes standardized according to the size of the valve and even if this space is restricted, the bolts can be screwed through all the bolt holes present in the flanges, without cause any problems. Consequently, by tightening the bolts with the nuts, the valve can be mounted between the piping elements without any difficulty.

Although the space between adjacent bolts to allow the cover flange neck to pass through it is narrow and the cover flange neck is narrowed at the points corresponding to the bolts to form a narrow section inside of the same, it is not necessary to narrow the neck of the cover flange in the direction of the extension of the bolts themselves.

The area to allow the passage of the pressurized fluid, which passes through the inside of the neck of the cover flange at the point corresponding to the restricted section, can be suitably configured without causing any difficulty in the actuation of the main valve by the section. command of the same. Consequently, the function of a pilot valve can be more satisfactorily realized.

The coupling surface of each terminal connection section to be coupled to each flange of the pipes is equipped with a recess in the shape of an annular groove, and a sealing element is inserted in the annular groove. At the time of piping installation, by simply bringing the connection terminal sections into contact with the pipe flanges, the connection terminal sections and the pipe flanges are connected tightly with the sealing element interposed between them.

Consequently and according to the present invention, as described above, the terminal connection sections and the flanges of the pipes can be easily coupled together airtight, without any effort. In a piping installation operation for a conventional wafer valve, to interleave a sealing element such as a gasket between the connecting end sections and the piping flanges, the sealing element must be suspended and coaxially aligned between the piping flanges and the connecting end sections having a diameter smaller than that of the piping flanges, supporting the valve so that the valve end connecting section can be coaxial with the piping flange, so as to connect the sections pipe terminals and flanges. This operation is very annoying and requires a lot of effort. The present invention has eliminated these difficulties, significantly improving operational efficiency. Consequently, the practical advantages of the present invention are considerable.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a front view illustrating a piping system of a wafer-shaped pilot valve.

Figure 2 is a top view of the valve.

Figure 3 is a cross-sectional view taken along an X-X line of Figure 1.

Figure 4 is a longitudinal cross-sectional view of the valve. Figure 5 is an enlarged cross-sectional view at one end, taken along the Y-Y line of Figure 4.

DETAILED DESCRIPTION OF THE PREFERRED REALIZATION OF THE INVENTION

An example of embodiment of the present invention will be described below with the aid of the drawings.

It is an assembly that opens and closes a main valve 2 enclosed in a main body 1, controlling a pilot valve 3 so as to increase or reduce a driving force (i.e. a pressure difference between a pressure on the primary side and a secondary side pressure) required to operate the main valve 2.

Specifically, the valve illustrated is a pressure reducing pilot valve, the main valve 2 of which, which is enclosed by the main body 1 arranged in a main pipeline, operates by using as the driving force a pressure differential between the primary side pressure and the secondary side pressure. A pressure reducing valve with a small diameter opening equipped with a force balancing mechanism is used as a pilot valve 3.

A pressure controlled by the pilot valve 3 is supplied to a control section 4 of the main valve 2, so that the main valve 2 connected to the control section 2 opens and closes a flow path 5 included in the main body 1 and communicating with the main pipe.

The main body 1 comprises a valve housing 6 through which the flow 5 passes (i.e. the primary side passage 5a and the secondary side passage 5b), and a control section 4 present in the valve housing 6 to control the opening of the main valve 2 as a function of the variation in pressure supplied by the pilot valve 3. In the piping system of the main body 1, the valve housing 6 is sandwiched between the flanges F, F1 of the piping provided at the connection ends of the elements of the pipes P, P1 which make up the main pipes. The bolts B, B1 (long thread) screwed through the flanges F, F1 of the pipes are secured with nuts N, N1, so that the valve housing 6 is interposed and supported between the flanges F, F1 of the pipes.

The valve casing 6 has an inlet 7 and an outlet 8 on its left and right sides, to allow the entry and exit of a pressurized fluid. The valve casing 6 also delimits the flow path of the primary side 5a and the flow path of the secondary side 5b, which communicate respectively with the inlet 7 and the outlet 8.

A dividing wall 9 is placed in the center of the valve housing 6 to separate the primary side flow path 5a and the secondary side flow path 5b into an upper section and a lower section. The dividing wall 9 has an opening of the main valve 10 for putting the flow paths 5a, 5b in communication with each other, and the flow path 5 extending from the inlet 7 and the outlet 8 is constructed so as to take an S shape.

The valve body 6 also has no flanges in its terminal connection sections 11, 12 intended to be coupled to the flanges F, F1 present on the inlet 7 and the outlet 8 of the flow path 5, so as to be sandwiched between the flanges F, F1 of the pipes.

In this way, the interfacial dimension of the valve housing 6 is shorter than that of a conventional flanged valve than the thickness of the relative flanges.

An annular groove 13 is obtained on the coupling surfaces of the connection terminal sections 11, 12 intended to be coupled to the flanges F, F1 of the pipes. A sealing element 14 such as e.g. an O-ring or a flat gasket are inserted in the annular groove 13 (in the example shown here an O-ring is inserted).

From the upper section of the valve housing 6, a neck 18 extends upwards.

The neck 18 presents at the top a recess 17 with an essentially rounded vase shape. The upper end section of the recess 17 is surrounded by a body cover flange 15 (i.e. a flange for connecting to a cover 16, which will be described later).

The neck 18 is mounted between the flanges F, F1 with its connecting end sections 11, 12 in contact with the flanges F, F1 and with bolts B, B1 screwed through the flanges. The neck 18 is also adapted to pass through a space between the adjacent bolts B, B1 along the perimeter of the flanges (in the example illustrated here, the bolts B, B1 are screwed, adjacent to each other, through the sections upper flanges F, F1).

The lid 16 is essentially in the shape of an inverted round plate. Its downwardly open end is surrounded by a flange 16a corresponding to the body cover flange 15.

The recess 17 and the cover 16 are coupled together by means of a diaphragm 19, and their respective flanges 15, 16a are fixed with bolts (some of these are eyebolt bolts). The diaphragm 19 divides the internal space created between the recess 17 and the lid 16 into a lower space (i.e. a space within the recessed section 17) and an upper space (i.e. a space inside the lid 16).

An adjustment spring 20 is placed inside the cover 16, and the space inside the cover 16 consists of a pressure chamber 21, so as to create a control section 4.

The adjusting spring 20 consists of a spiral compression spring inserted in the compressed state between a compression element 22 of the diaphragm coupled centrally with the upper surface of the diaphragm 19, and the upper central part of the cover 16.

The recess 17 is open so as to communicate with the flow path on the primary side 5a through a space that allows the passage of the pressurized fluid contained in the neck 18, and also so that the lower section of the neck 18 corresponds to the opening of the valve 10. The dividing wall 9 has at its upper end the opening 23. The dividing wall 9 separates the flow path of the primary side 5a and the path in the passage 24 (i.e. the space inside the neck 18 contiguous to the primary side flow path 5a from secondary side flow path 5b).

Passage 24 is typically in the shape of a cylinder, as illustrated by a single dotted line in Figure 5. In contrast, in this embodiment, passage 24 has a narrow section 25 and a cylindrical rectangular shape in the narrow section 25 shown in Figure 5, for the following reasons. As described above, the neck 18 is mounted between the bolts B, B1 screwed adjacent to each other within the upper sections of the piping flanges F, F1 when the valve housing 6 is mounted. For this purpose and as illustrated in Figure 3, the neck 18 is restricted to an essentially rectangular, cylindrical shape on its side walls corresponding to the bolts B, B1 adjacent to the passage 24, so as to form the restricted section 25. To form the section narrow 25, the neck 18 is narrowed along its side walls, so that their distance becomes less than that between the bolts B, B1, which will vary according to the type of the flanges F, F1 of the pipes, chosen according to the size of the valve. The passage 24 therefore assumes an essentially rectangular shape, cylindrical in the restricted section 25, as illustrated in Figure 5.

In this embodiment the length of the neck 18 is only slightly longer than the outer diameter of the bolts B, B1, as shown in Figure 3. The outer width D (see Figure 5) of the neck 18 corresponding to the width direction of the passage 24 ( i.e. the direction perpendicular to the direction along which the bolts B, B1) are screwed is reduced so as to be less than the distance between the bolts B, B1 along its entire length, so as to create the narrow portion. Conversely, when the length of the neck 18 is considerably longer than the outer diameter of the bolts B, B1, it is desirable that the neck 18 be restricted only in the points along its lateral parts which correspond to the bolts B, B1, while the remaining points along the side walls of the same not corresponding to the bolts B, B1 do not have restrictions, as illustrated with a single dotted line in Figure 5. The neck 18 can thus be reinforced in its restricted section 25.

The passage 24 further comprises only one valve stem 26 passing through it, as will be described later. The valve will operate smoothly as long as the pressurized fluid can still pass through the passage 24 into the restricted section 25 in line with the valve stem 26 passing through the passage 24. In any case, however, as the pressurized fluid is met with a restriction in the restricted section 25, in order to achieve a better functionality of the main valve 2, it is desirable that the restricted section 25 has an area as large as possible to allow the passage of the fluid under pressure. For this purpose it is more preferable that the restricted section 25 is formed only by narrowing the side walls of the neck 18 at the points adjacent to the bolts B, B1.

Flanges F, F1 are chosen in accordance with the standards and the size of the valve. The distance between bolts B, B1 varies according to the type of flanges F, F1 of the pipes used. Even where the distance between the bolts B, B1 is scarce and the passage 24 is narrowed in the direction of its width to form the narrow section 25, it is sufficient to restrict the neck 18 at the points along its side walls adjacent to the bolts B, B1.

It is not necessary to narrow or bring the side walls of the neck 18 together in the screwing direction of the bolts B, B1. The passage 24 can therefore reserve a predetermined area for passing the fluid under pressure through its restricted section 25, without causing any difficulty to the main valve 2 with the control section 4.

A membrane receiving element 27 is coupled to the center of the lower surface of the diaphragm 19. The upper and lower sections of the diaphragm 19 are interposed between the receiving element of the diaphragm 27 and the compression element of the diaphragm 22. In this state the valve stem 26 penetrates through these three elements 19, 22, 27 in their central sections, so as to integrate these three elements 19, 22, 27 and the valve stem 26 in a single unit.

A support cylinder 28 with a diameter smaller than that of the adjustment spring 20 also protrudes from the center of the lid 16 vertically towards the inside and outside of the lid. A flow rate adjusting rod 29, with a guide hole 29a formed therein and extending from the lower end of the rod 29 upward for a predetermined length, is screwed into the support cylinder 28 in a state a air tightness. In this way, the upper end of the valve stem is inserted smoothly into the guide hole 29a of the flow rate adjustment bar 29.

The lower end of the valve stem 26 penetrates through the main valve 2 to open and close the opening 10 of the main valve, thereby operating the main valve 2. Thus, the main valve 2 and the control section 4 they are connected to each other through the valve stem 26.

The main valve 2 is mounted in a detachable way on a seat 30 present on the upper end of the opening 10.

The opening of the valve 2 is controlled by the displacement of the diaphragm 19.

The lower end of the valve stem 26 is made to slide smoothly through a cylindrical guide section 31 present at the lower end 10 of the main valve opening. The cylindrical guide section 31 couples the upper ends of a plurality of support arms 32 which project radially from its outer perimeter towards the lower opening end of the main valve opening 10. Thus, the distance between the arms adjacent support 32 communicates with the opening 10 of the main valve so as to allow the passage of the fluid under pressure.

The pressure adjustment bar 29 is then moved up and down to adjust the distance between the upper end of the valve stem 26 and the upper end obstructed in the guide hole 29a. In this way, the upper limit of the valve stem 26 is restricted, and the lift of the main valve 2, i.e. the flow rate of the fluid under pressure, is adjusted. It is also possible to move the flow rate adjustment bar 29 to bring the obstructed upper end of the upper section into the guide hole 29a in contact with the upper end of the valve stem 26, so that the main valve 2 is forced to close completely, and that the water flow can be stopped on the primary side.

Pilot valve 3 is a directly operated pressure reducing valve coupled to valve body 33 via stem 34. Pilot valve 3 comprises a section with a force balancing mechanism 38 consisting of a diaphragm 36 which moves manually as the pressure in a secondary side pressure chamber 35 changes and a pressure regulating spring 37 moves the diaphragm 36 in a direction along the valve body 33. A valve housing 39 of the pilot valve comprises, at its right and left ends (i.e. at the top and bottom sides in Figure 3) a primary side pressure chamber 42 and a secondary side pressure chamber 35 which respectively communicate with an inlet 40 and an outlet 41 for a fluid under pressure, and are separated from each other by a partition wall 43. The partition wall 43 allows the pressure chamber on the primary side 42 and the pressure chamber on the secondary side 35 to communicate each other through a valve opening 44 which is opened and closed by the valve body 33. A diaphragm 36 is interposed between the upper section of an upwardly open valve housing 39 (i.e. the left side in Figure 3) to communicate with the pressure chamber 35 on the secondary side, and a spring cap 47 is screwed onto an adjustment screw 46 which compresses the pressure adjustment spring 37 in the opening direction of the valve, by means of a spring compression element 45.

The pilot valve 3 is not to be limited to the structure described above, but can have any other structure, as long as it has a pressure reducing function capable of maintaining the pressure on the secondary side at a certain constant pressure value lower than that of the side pressure. primary.

The inlet 40 of the pilot valve 3 is then connected to the flow path of the primary side 5a of the main body 1 through a first piping path 48, while the outlet 41 of the pilot valve 3 is connected to the flow path of the secondary side 5b of the main body 1 through a second path of the pipe 49.

The first route of the pipe 48 branches at some point to go to the pressure chamber 21. A “T” shaped pipe fitting 50 is provided on the branch section, with three-way connection openings.

In connection 50, the coaxial upper connection opening and lower connection opening are respectively connected with a coupling pipe 48a for coupling to the pilot valve 3 (hereinafter known as pilot coupling pipe 48a) and a coupling pipe 48b for a coupling to the primary side flow path 5a (hereinafter known as the primary side coupling pipe 48b). The lateral connection opening perpendicular to the upper and lower connection openings is connected with a coupling pipe 51 for coupling with the pressure chamber 21 (later known as branch pipe 51) (see Figure 4).

The outlet of the primary side coupling pipe 48b and the inlet of the pilot coupling pipe 48a, opposite each other inside the coupling element 50, are respectively formed with an outflow restriction opening 52 and an inlet throttle opening 53 having a diameter smaller than that of the coupling pipes 48a, 48b. The restrictor port 52 and the restrictor port 53 regulate the flow rate of the pressurized fluid, through the pilot coupling line 48a and the branch line 51, respectively to the pilot valve 3 and the pressure chamber 21, so as to avoid sudden variations in pressure inside the pressure chamber of the primary side 42 of the pilot valve 3 and inside the pressure chamber 21.

To mount the wafer-shaped pilot valve structured as described above, the connection end sections 11, 12 of the valve housing 6 are respectively coupled to the flanges F, F1 of the pipelines. Bolts B, B1 are respectively screwed through the bolt holes of the flanges F, F1.

With the bolts B, B1 adjacent to each other screwed through the upper sections of the flanges F, F1 of the pipes, the neck 18 passes through the space between the bolts B, B1. In this case the neck 18 is configured with the narrow section 25 adjacent corresponding to the bolts B, B1, and the neck 18 is then made to pass through the space between the bolts B, B1 without hindering the presence of the bolts. A plurality of bolts B, B1, _ arranged along the perimeter of the flanges F, F1 of the pipes is then uniformly fixed with the nuts B, N1, ... so that the valve is interposed and fixed between the elements P, P1 of the piping.

As a consequence of the fastening of the bolts B, B1, ... with the nuts N, N1, ... the sealing element 14 inside the annular groove 13 formed in the respective connection end sections 11, 12 deforms elastically and strongly adheres to the terminal connection surface of the respective flanges F, F1 of the pipes intended to be coupled to the respective terminal connection sections 11, 12. Consequently, the terminal connection sections 11, 12 and the flanges F, F1 of the pipes are respectively strongly adhering to each other.

In the valve thus arranged, the pilot valve 3 controls the pressure supplied to the pressure chamber 21 of the main body 1. In other words, the pilot valve 3 increases the pressure inside the pressure chamber 21 in accordance with the force exerted by the spring control 20 which helps to close the valve and force downwardly against the diaphragm 19 in the closing direction of the valve. On the contrary, the pilot valve 3 lowers the pressure inside the pressure chamber 21 to give rise to an upward force exerted by the pressure of the primary side against the diaphragm 19 in the opening direction of the valve. The downward force and the upward force exerted against the diaphragm 19 are balanced, to control the opening of the main valve 2, so as to maintain the secondary side pressure at a certain constant pressure below the pressure of the primary side.

In this embodiment, a pressure reducing valve is selected as an example for the wafer-shaped pilot valve, in which the pilot valve 3 consisting of a direct acting pressure reducing valve having a small diameter opening is connected to main body 1. The wafer-shaped pilot valve is not necessarily a pressure reducing pilot valve, however, but may alternatively comprise other types of pilot valves such as a pressure regulating pilot valve (i.e. a back pressure valve, a differential pressure valve and the like), an electromagnetic type pilot valve, a water level control pilot valve, and the like. In these alternative examples, as in the case described above, the connecting end sections 11, 12 of the valve housing 6 of the main body valve 1 are constructed to be without flanges, and the neck 18 extending from the valve housing 6 towards the The top is formed by the restricted section 25. The neck 18, at the point formed by the restricted section 25, can be passed through the space between the adjacent bolts B, B1 and screwed through the upper sections of the flanges F, F1 of the pipes. .

In this embodiment, the pilot valve 3 and the main body 1 are separated from each other. Alternatively, the pilot valve 3 and the main body 1 may be present in a single integrated piece, as in the case of the pilot valve described in the patent document 1, to the extent that the integral structure is applicable to the present invention. In this alternative example, as in the case described above, the cover neck enclosing the main valve is formed in the restricted section.

Claims (2)

CLAIMS 1. Wafer-shaped pilot valve that uses a pilot valve to control a motive force required to operate a main valve to open and close the main valve, comprising a valve housing enclosing said main valve, where: - said valve is sandwiched between pipe flanges fixed together with nuts and bolts, said valve casing has no flanges in its terminal connection sections to connect to said pipe flanges and is respectively equipped with an inlet and a 'outlet for a pressurized fluid; - a cover neck extends upwards from said valve housing, said cover flange neck includes a space to allow the passage of a fluid under pressure; - a valve stem passes through said neck, and couples said valve with a control section to control the opening of said main valve as a function of a variation in the pressure fed by said pilot valve, wherein said cover flange neck is restricted, only in the points along its side walls corresponding to said adjacent bolts, to a width less than that of a space between said bolts which varies according to the type of said pipe flanges selected according to a size of said valve, so that said cover flange neck can be passed through the space between said bolts extended between said flanges of adjacent pipes along the perimeter of said pipe flanges. 2. Wafer-shaped pilot valve according to claim 1, in which a coupling surface of each of said coupling end sections to be coupled to said pipe flanges has an annular groove, and a sealing element is inserted in said annular groove.